The evolutionary function of religion

In his trailblazing book Darwin’s Cathedral, the biologist David Sloan Wilson proposes that religion emerged as a stable part of all human societies for a simple reason: it made them work better. Human groups that happened to possess a faith instinct so thoroughly dominated non-religious competitors that religious tendencies became deeply entrenched in our species.

Wilson argues that religion provides multiple benefits to groups. As the sociologist Émile Durkheim wrote, “Religion is a unified system of beliefs and practices … which unite into one single moral community called a Church all those who adhere to them.” Second, religion coordinates behavior within the group, setting up rules and norms, punishments and rewards. Third, religion provides a powerful incentive system that promotes group cooperation and suppresses selfishness. The science writer Nicholas Wade expresses the heart of Wilson’s idea succinctly: the evolutionary function of religion “is to bind people together and make them put the group’s interests ahead of their own.

If you’re skeptical

Wilson points out that “elements of religion that appear irrational and dysfunctional often make perfectly good sense when judged by the only appropriate gold standard as far as evolutionary theory is concerned-what they cause people to do.” And what they generally cause people to do is to behave more decently toward members of the group (co-religionists) while vigorously asserting the group’s interests against competitors. As the German evolutionist Gustav Jager argued in 1869, religion can be seen as “a weapon in the [Darwinian] struggle for survival.”

The darkside of religion

There are good things about religion, including the way its stories bind people into more harmonious collectives. But there is an obvious dark side to religion too: the way it is so readily weaponized. Religion draws co-religionists together and drives those of different faiths apart.